[4788] in cryptography@c2.net mail archive
Re: quantum codebreaker
daemon@ATHENA.MIT.EDU (Mike Stay)
Mon May 24 14:24:03 1999
Date: Mon, 24 May 1999 10:34:40 -0600
From: Mike Stay <staym@accessdata.com>
To: coderpunks@toad.com
Cc: cryptography@c2.net
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--
Mike Stay
Cryptographer / Programmer
AccessData Corp.
mailto:staym@accessdata.com
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>From slloyd@MIT.EDU Mon May 24 10:23:14 1999
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To: staym@accessdata.com
Date: Mon, 24 May 1999 12:23:00 EDT
Sender: slloyd@MIT.EDU
Dear Mike,
I think you've overestimated the implications of this method for
code breaking. My previous work with Dan Abrams did indeed show
that nonlinear quantum mechanics could be used to solve
NP and #P oracle problems (which in my opinion should be
regarded as evidence against nonlinear quantum mechanics).
The idea is to use the nonlinearity to amplify small differences
in the wave function. The feedback method described in the current
paper could also be used to amplify small differences: accordingly,
you could use it to solve hard problems by the same method.
The catch is that order to amplify differences of the size
1/N, you need N copies of the same system. So to solve
exponentially hard problems by this feedback method, you
need exponentially many copies (we're up front about this
in the paper). Cryptography remains as safe as it was before.
Which is a lucky thing, since I'm about to use the web to buy
some plane tickets.
Yours,
Seth
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